Improvement in vacuum-chambers for car-brakes



2 Sheets-Sheet 1.

T.cooPER. VACUUM CHAMBERS FOR CAR-BRAKES.

Patented Nov. 21,1876.

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, 'r., COOPER; VACUUM CHAMBERS FOB. CAR-BRAKES.

Patented Nov. 21.1876.

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Y um-chamber t'or a car-brake UNITED STATES PATENT CDEEIGE.4

THEODORE COOPER, OF WARWICK, RHODE ISLAND.v

IMPROVEMENT IN VACUUM-'CHAMBERS FOR CAR-BRAKES.

Specification forming part of Letters Patent No.`184,46 l, dated November'Ql, 1876 application led April 6, 1876.

To all whom it may 'concern v Be it known that I, THEoDoEE COOPER, of

.Warwick, in the countyof Kent and State ,of

which the pressure of the atmosphere is ex-l erted for furnishing the power requisite for actuating the car-brake mechanism,

It is well known to beessential that a vacuum-chamber should be longitudinally collapsible to an extent or degree which will, at least, admit of such a movement of its head as is requisite to effect the movement of the several parts of the brake mechanism which are controlled by the chamber; also, that the head or heads of said chamber should have such a superiicial area as'will enable-them, with an attainable or desirablevacuum,to afford sufficient surface for atmospheric pressure to securethe requisite power for properly settingthe brakes; also, that the longitudinally-collapsible chamber should be laterally non-collapsible without impairing its longitudinally collapsible capacity.

It is obvious that it is of value that the number ot' joints in these chambers be reduced as far as possible, because air -tight joints are requisite, and they are not readily attained at'A the outset, nor easily maintained when subjected to the various unfavorable conditions incident to their practical use. There is still vanother point of great practical value, to which, so far as my knowledge extends, no attention has been givenv prior to my present invention. After long-continued study ofthe subject, attended with numerous experiments and tests, I have demonstrated .that a vacushould have a normal interior cubical capacity no greater than is absolutely requisite for permitting the required movement of its head orheads, and

affording onV the exterior of said heads a proper pressure area to secure the requisite power for setting and holding the brakes. The value'of this feature will be readily comprehended when it is considered that it involvesy not only economy in operation, but also promptness in action.

It willbe seen, whether the air be exhausted from a chamber by means of an air-pump or by -means of a steamjet, that the labor of the pump and the volume of. steam in the jet required for thatservice will be proportionate to the interior cubical capacity of the vacuum-chamber; and, further, that in proportion to the interior capacity of the chamber, it will be prompt or slow in its action, because a pump or steam-jet can more promptly exhaust the air from a small chamber than from a` larger one, other controlling conditions being equal.

I have practically attained, by reason of my invention, a vacuum-chamber which meets fully all of the heretofore well-known re'quire-v ments, and possesses the novel features vof value which I have recited; and my invention consists, mainly, in a vacuum-chamber for carbrakes having sides composed, in whole or iny part, of iiexible material suitably stiffened,

peripherically arranged to collapse longitudinally a head to which the brake mechanism is connected, and tapered, so that it is larger at the end to which this'head'is attached than at the opposite end.` In such a chamber' the requisite area of head is provided for, while the interior capacity is reduced to a minimum, because the chamber is larger at the head than at the opposite end, having an outline like a frustum of a cone laterally or peripherically grooved.

My invention further consists in a vacuumchamber longitudinally collapsible, having al suitable head or heads, and clamping-rings with corrugated sides, composed of molded vulcanizable gum or gum compound ot' asuitable nature, and'interior annular braces or stitfeners, which-are embedded in the gum, and are practically inseparable therefrom. Such a chamber requires no joints except at its two ends, the'braces or stitt'eners are a1- ways maintained 'in their proper relative positions, and the exible material, being molded, is not unduly liable to crack or break at the recesses between the braces.

It will be seen that this last-recited'portion of my invention is not limited to a chamber smaller at one end than at the other, because, whether the sides of' the chamber be straight or inclined, equally valuable results will accrue by reason of the ,molded gum and the annular braces embedded therein.

To more particularly describe my invention, I will refer to the accompanying drawings, of which there are two sheets, and in which- Figure 1, Sheet 1, represents, in side View, two of my vacuum-chambers united to a central metallic chamber, so that the three constitute a double vacuum chamber. Fig. 2, Sheet 1, represents the double chamber in Iongitudinal central section.` Fig. 3 represents the same in end view. Fig. 4 represents, in end view, the-central metallic chamber. Fig. 5 represents the central chamber in side view. Fig. 6, Sheet 2, represents, in side view, my double chamber collapsed, and guiding devices desirable for maintaining the head-rods in a line parallel with the axial line of the chambers. Figs. `7 and 9 represent, in side and edge views, clamping-rings, `by which the` ends of a chamber are secured to a neck on the central metallic chamber, and toa head, respectively. Fig. 8 represents, in end view, the apparatus `shown in Fig. 6. Fig. 10 represents, in central longitudinal section and end Iview, the head ot' a chamber. represents live annular braces, which are embedded in the flexible sides of the chamber; Fig. 12 represents, in section, a coupling-connection desirablefor uniting a head-rod with a brake-rod beneath a car.

In each instance, A and A' denote the collapsible tapering portions of the vacuumchamber. They should be made of fine gum, carefully compounded, so as to be strong and durable. They are vulcanized in a mold es peciall y designed for the purpose. The method of manufacture, and the special means employed therein, constitute the subject of a separate application` for Letters Patent. l The annular braces shown in Fig. l1 are numbered consecutively, Vcommencing at the largest. '.lhey occupy positions indicated in Fig. 2, and, being embedded in the gum, it is practically impossible for them subsequently to get out of place. Each end of the corrugated liexible portion is provided with a plain neck, which is parallel with the axial line of the chamber.

The central metallic chamber at Ris provided with a suitable .ilange for securing it to a car-frame, and has an opening, as at K,

Fig. 1].4

Fig. 4, to admit ofthe proper location of brakerods when employed in connection. with handbrakes.

chamber by means of the necks S S and the` clamping-collars F and F. `(Shown in Fig. 2.) The working-heads of the chamber are shown at U and U', and the flexible portion of the chamber is secured thereto by means of flanges on the heads and the clamping-collars E and E', are concaved, as shown, presenting an extensive exterior area, andare provided with .central necks, to which the head-rods V and V are respectively connected. These rods are shown in Fig. 6 to be provided `with frictionless guides, consisting in each. instance of `four anti-friction pulleys with grooved peripheries, l

arranged to encircle the rod `and maintain it` in a position coincidentwitb theaxial line ot the chamber. The, small figures in Fig. "6, atl and 2, show the head-rod hangers and frictionless guides, while at 3 and 4 the con-` nections of the head-rods with the brake-rods y are shown in side view. 1n Fig.` 12 one of these connections is shown in detail, to beprovided with a gib and tapering pin, whereby a close unity of the two rods may be maintained.

In Fig. 6 the chamber `is shown tobe l fully contracted,'as l if exerting power on the brakes. The exible material can assumano form or shapewhilein service which is not in harmony with the lines predetermined inttha mold, and therefore its liability to-crack `or break is reduced to a minimum, as I believe, or at least that liability is thereby guarded against as far as is practicable.

Having thus described my invention, I claim as new and desirefto secure by these Letters Patent- 1. A tapered vacuum-chamber, composed in` 'part of flexible material, substantially as described. l 2. A molded seamless corrugated vacuumchamber, having sides composed of liexible material, and provided with internal annular braces or stiiieners, embedded in said `material, substantially as described.`

, THEODORE COOPER.

Witnesses:

J. C. B. WooDs, `THOMAS F. OosGRovE.

The interior portion of this chamber is shown at H, Fig. 2, with which the brauch respectively. The heads UandU 

